Who (Self) Admits Technical Debt?

Self-Admitted Technical Debt (SATD) are comments, left by developers in the source code or elsewhere, aimed at describing the presence of TD, i.e., source code "not ready yet". Although this was never stated in the original paper by Potdar and Shihab, the term SATD might suggest that it refers to a "self-admission"by whoever has written or changed the source code. This paper empirically investigates, using a curated SATD dataset from five Java open-source projects, (i) the extent to which SATD comments are introduced by authors different from those who have done last changes to the related source code, and (ii) when this happens, what is the level of ownership those developers have about the commented source code. Results of the study indicate that, depending on the project, the percentage of SATD admissions introduced or changed without modifying the related source code varies between 0% and 16%, and therefore represent a small, yet not negligible, phenomenon. The level of ownership of those developers is not particularly low, with a median value per project between 10% and 42%. This indicates the possible use of SATD as a different way to perform code review, although this behavior should be considered sub-optimal to the use of more traditional tools, which entail suitable notification mechanisms.